Increased Circulating Concentration of the N-Terminus of the Atrial Natriuretic Factor Prohormone in Persons with Pheochromocytomas

To investigate the possible relationship of hypertension and the N-terminus of the atrial natriuretic factor (ANF) prohormone which contains two peptides [i.e. pro ANF-(1–30) and pro-ANF-(31–67)] with blood pressure-lowering effects, we examined the circulating levels of the N-terminus of the ANF prohormone in three patients with pheochromocytomas before surgery, during an increase in their blood pressure with surgical manipulation of their tumors, and after surgery when their blood pressures returned to normal. The circulating levels of the whole N-terminus [amino acids 1–98; pro-ANF-(1–98)] and pro-ANF-(31–67) from the midportion of the N-terminus of the ANF prohormone were increased 2-fold in patients with both extraadrenal and intraadrenal pheochromocytomas. In both the intraadrenal and extraadrenal patients N-terminus [pro-ANF-(1–98)] and pro-ANF-(31–67) circulating levels increased further during surgical manipulation and returned to normal after surgical removal of their respective tumors. Each of ...